Handheld firearms may be generally classified into longarms and short arms, with short arms including pistols and revolvers, and longarms including rifles and shotguns. The following principles described here apply generally to all types of firearms, but for convenience unless specified otherwise, these principles are illustrated with respect to rifles. For instance, when holding any item of weight with arms outstretched from the body, muscle fatigue increases with either (a) an increase in the weight, or (b) an increase in the distance of the weight away from the body.
To assist in this discussion, FIG. 8 shows a prior art shooting system where a shooter S is readying to shoot a rifle R. The illustrated rifle R is an M16A4 rifle currently issued to United States soldiers worldwide, and used by law enforcement, as well as by civilians for a variety of uses including plinking, target shooting, hunting, competition, etc. The rifle R is shown shouldered in a shooting position by a United States infantry soldier S. As equipped, the illustrated rifle R has a center of gravity approximately located along dashed vertical line CG1. As the center of gravity line CG1 moves away from shooter S, muscle fatigue increases, and vice versa.
The illustrated rifle R has a two-part frame known as a “receiver,” comprising an upper receiver UR and a lower receiver LR, to which a stock portion A is attached. The stock A extends from the lower receiver LR toward the shooter S to terminate in a butt portion B. The lower receiver LR defines a magazine well MW which receives a supply of ammo preloaded into a magazine clip MC. The lower receiver LR also supports a trigger mechanism T and serves as a mount for a pistol-type grip G. A trigger hand TH (here, the dominant right hand) surrounds the grip G to position the index finger to engage the trigger mechanism T. During shooting, the trigger hand TH uses grip G to pull the rifle butt B snugly against the shooter's dominant-hand shoulder to absorb recoil forces.
A rifled barrel C is supported by the upper receiver UR and terminates at a muzzle M from which a projectile, such as a bullet, is expelled. The upper receiver UR interior defines a conventional firing chamber coupled to the barrel C. The upper receiver UR also defines a conventional ejection port for expelling spent ammunition (“ammo”) casings, and a conventional dust cover for keeping debris out of the firing chamber. The upper receiver UR also supports a conventional forward assist member which aids in loading slightly imperfect ammo into the firing chamber. Since these several items are all of conventional construction, they are omitted from FIG. 8 for clarity.
The rifle R also has a handguard assembly, referred to herein as a forearm F, which partially or fully surrounds a rear portion of barrel C. The non-dominant or “opposite” hand with respect to the trigger hand TH, serves as a support hand SH to hold the front portion of the rifle by resting forearm F in the palm of the support hand SH. Depending upon shooting conditions, the fingers and thumb of the support hand SH may or may not grip the rifle forearm F.
Today's law enforcement officers, as well as battlefield soldiers and others wear body armor typically constructed of an anti-ballistic fabric, ceramic, metallic or other energy absorbing, bullet retarding or deflecting materials, such as being worn by shooter S in FIG. 8. Body armor, whether worn under or over a shooter's clothing, positions the rifle butt B, and hence the entire rifle R, further away from the shooter's body than without armor. While body armor may prevent serious injury or death, it has several drawbacks in addition to being hot, it is bulky. This bulkiness of the body armor adversely affects shooting in three ways: (1) it changes target sight relief, (2) it changes cheek weld, and (3) it increases muscle fatigue.